Compressor



COMPRBSSOR- 3 Sheets-Sheet 1 Filed June 10, 1965 I I!!! r,

. w 7 w m w 5 v Al l 1 q 4/ s 3\ I III 4 4 I a v K Q g w 1 .h w w w x m 3 2 INVENTORS CECIL G. MARTIN BY WILLIAM E. BARTLEYJJI ATTORNEYS IIIf I I ///I I III I I /IIII Aug. 6, 1968 c G? MARTm ET AL COMPRESSOR 3 Sheets-Sheet 2 Filed June 10, 1965 INVENTORS CECIL G. MARTIN BY WILLIAM E. BARTLEYHI ATTORNEYS 6, 1963 c. G. MARTIN E L GOMPRES SOR 3 Sheets-Sheet 5 Filed June 10, 1965 ENTORS CECIL G fi IYIRTIN BY WILLIAM E BARTLEYJII ATTORNEYS.

United States Patent O 3,395,854 COMPRESSOR Cecil G. Martin, Cleveland, and William Edward Bartley III, Chagrin Falls, Ohio, assignors to Energy Technology, Inc., Cleveland, Ohio Filed June 10, 1965, Ser. No. 462,960 33 Claims. (Cl. 23075) ABSTRACT OF THE DISCLOSURE A compressor having a rotatable outer casing that carries a liquid ring and a rotatable wheel having peripheral cavities and eccentrically located within the casing, to be partially immersed in the liquid ring. The casing and liquid ring are rotated at a faster peripheral speed than the wheel and gas is compressed in the wheel cavities by utilizing kinetic energy of the moving liquid. The wheel cavities are shaped to effectively utilize the kinetic energy of the ring and convert it to static pressure.

This invention pertains to liquid ring mechanisms and more particularly to gas compressors of the liquid ring type.

There have been prior proposals for so-called liquid ring compressors or pumps. Some of these proposals, like the device of this invention, are applicable for use in vacuum pumps and expansion and internal combustion engines as well as liquid ring compressors. While the specifically disclosed structure is a compressor, it will be recognized most of the principles incorporated in this disclosure are applicable to all liquid ring mechanisms.

With liquid ring mechanisms, a casing is provided which has a cylindrical chamber. A rotating ring of liquid is within the chamber and maintained against the walls defining the perimeter of the chamber by centrifugal force. A compressor wheel is mounted eccentrically in the chamber and caused to rotate about its own axis. The wheel is equipped with cavities disposed adjacent one another around the perimeter of the wheel. When these devices are operated as compressors the cavities are sequentially immersed within the liquid ring causing gas to be trapped in the cavities. As a cavity with trapped gas continues to rotate, it moves closer to the wall of the casing cavity, becoming more deeply immersed in the liquid ring. This action causes, in prior proposals, the hydrostatic head above to compress the gas trapped within the cavity. Valving is provided to selectively permit the exhaust of the compressed gas from the wheel cavities.

Commercial structures embodying this principle which are presently available are pumps in which the casing is stationary. For a number of reasons, which will become apparent, these commercial devices must be operated at very low peripheral speeds of wheel rotation if they are to be operative. If any attempt is made to operate them at higher peripheral speeds, efllciency of compression diminishes as the speed of rotation is increased due to high friction of the high velocity liquid moving past the stationary casing wall.

In the past, proposals for liquid ring compressors in which the casing is rotated have also been made. These proposals have all been deficient for some if not all of the following reasons:

(1) Generally, no provision has been made to minimize skin and form drag hydrodynamic losses. Thus, there are significant losses as the fluid passes around the wheel.

(2) Prior proposals have ignored the Bernoulli principle of acceleration of any fluid past an obstruction. Thus, as the fluid moves relative to the wheel past it on either side, it must move through a relatively confined space.

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Since the space is confined, the fluid must accelerate. In a rotating liquid ring, this results in the fluid increasing in radial thickness and velocity as it passes the wheel, contributing to the creation of increased body drag and turbulence, and causing additional energy losses.

(3) In the usual arrangement, no provision has been made for replenishing liquid energy loss other than by power to the liquid ring supplied by the wheel. This has proved to be very ineflicient.

(4) Except in those cases where attempts have been made to drive the casing, no provision is made for the external windage and bearing frictional losses experienced by the casing as it rotates, except through fluid friction between the liquid ring and the housing. This energy transmission through fluid friction is highly inefficient and substantial efficiency losses are the result.

(5) Typically, no provision is made for venting the compression cavities as they exit from the liquid ring and this results in cavitation, turbulence, and noise. It also results in early destruction of the device if it is operated at high speed.

(6) The curvature of blades of the wheel has generally been such as to create a high velocity depressed core in the main liquid body, increasing losses of energy. This depression reduces the hydrostatic head obtained when the wheel is immersed.

(7) These proposals have failed to make provision for a means to inhibit the formation of harmonic waves which can be destructive to the structure.

(8) Check valves often used to control the escape of compressed gas from the wheel cavities operate against centrifugal force. Accordingly, considerable efficiency is lost because once the pressure of the compressed gas has dropped below the combined opposing force of the pressure on the exhaust side of the valve plus centrifugal force, no further gas can escape. Furthermore, liquid carryover trapped behind the check valves adds to the opposing force.

All of these and other disadvantages of prior proposals have been overcome by this invention. In addition, a new principle of operation has been discovered, the utilization of which produces substantial increases in efiiciency and the ability to obtain high compression pressure. The operation of the compressor of this invention is, in a sense, opposite to the typical prior construction. The principle of this discovery is that in the device of this invention gas compression is obtained primarily through the utilization of the liquid ring kinetic energy. By comparison, the prior art proposals have each been designed to compress solely through the utilization of a hydrostatic head; i.e., by depressing trapped gas below the liquid level. Thus, these devices operated on the same principle as immersing an empty bottle in an inverted condition into a body of water. The further the bottle is immersed, the greater the compression of gas trapped within the bottle.

One feature of this invention is an efiicient liquid coupling devised so that the rotating casing efficiently drives the liquid ring, transmitting energy to it. This coupling attempts to force the liquid ring and casing to rotate together at the same speed. The coupling has a pump-like action and due to this and the rotation of the liquid ring, there is also a strong suppression of surface deformations in the liquid ring, such as the wake behind the wheel.

As suggested above, another feature of the invention resides in the utilization of kinetic energy to cause compression. This kinetic energy principle is obtained 1) due to the liquid coupling; (2) by rotation of the casing and liquid ring at a relatively high peripheral speed and the wheel at a relatively lower peripheral speed; and (3) due to a novel formation of the wheel. The wheel is made so that the entrance to each of its cavities is relatively small,

the cavities thereafter increasing to a relatively large crosssectional area. These cavities are each mechanical diffusers. The liquid flows into the wheel cavity diffusers at an initial high velocity due to the high speed rotation of the liquid ring relative to the wheel. This initial high velocity is reduced as the liquid flows within the cavities due to the cavities functioning as diffusers. Since total pressure remains substantially the same, a reduction in the liquid velocity results in an increase in the static pressure as the liquid flows within the cavity diffuser. Thus, the kinetic energy of the velocity is converted to static pressure energy.

A further feature of the invention is that the construction of the wheel with these mechanical diffuser chambers permits the wheel to be tapered to a relatively narrow width at its perimeter. This results in streamlining of the wheel which substantially reduces the form drag energy loss between the wheel and the rotating liquid ring.

An important feature of the invention is the provision of a substantial unobstructed area for the passage of liquid between the wheel and the casing and coupling. Defining the liquid ring area as that maximum liquid crosssection normal to the liquid peripheral velocity prior to wheel contact, at least 20 percent of this same crosssection shall be unobstructed by the wheel at the point of maximum submergence of the wheel in the liquid ring. This relationship is particularly important and advantageous where the peripheral velocity of the casing is significantly greater than that of the wheel and where the ring is effectively coupled to the rotated casing.

Another advantage of this invention is that, since the device operates on a kinetic energy principle as well as a hydrostatic energy principle, the wheel is not immersed as deeply in the liquid ring as has been the case heretofore. Specifically, useful compression can be obtained with the present invention at any depth of immersion of the blades up to the root of the wheel cavities, whereas prior devices, operating on a principle of a hydrostatic head, required submergence of the cavity root with attendant high frictional and body drag losses between the wheel and the liquid ring.

Still another feature of the invention resides in the formation of the blades which define the wheel cavities so that the blades are curved slightly backwards from the direction of rotation. These blades act as scoops for the relatively higher velocity liquid. The kinetic energy of the liquid thus becomes available to compress the gas in the wheel cavity.

An important feature of the invention resides in the provision of ports for the cavities. The novel ports of this invention have no moving parts so that there is no loss of energy due to centrifugal force acting on valve components. In addition, the ports of this invention provide both efiicient exit of compressed gas from each cavity and venting of the cavity immediately after the compressed gas has been vented out. This venting of each cavity prevents formation of a vacuum within the cavity and greatly reduces the cavitation and drag losses experienced as the cavity exits from the liquid ring.

A further important feature of this invention is the suppression of waves which are formed on the surface of the liquid ring. Such wave disturbances are formed by minute imbalances inherent in any rotational movement. The amplitude of these waves tends to continually increase due to natural frequencies or harmonics that reinforce the disturbances. Where high speeds of rotation are involved, wave amplitudes, if unsuppressed, would rapidly build up with attendant noise and destructive forces. In accordance with this invention, wave amplitudes are suppressed to a negligible level by providing auxiliary surfaces adjacent the casing side walls and adjacent the liquid surface. More specifically, such surfaces may be provided extending concentrically with the nominal liquid surface. These auxiliary surfaces intercept portions of the wave crests as they are formed and thereby dissipate the energy of the waves, preventing their build-up to destructive levels.

In the preferred arrangement of this invention the wheel and the casing are both constructed symmetrically about a radial center plane and the wheel is located within the casing so that the center plane of the wheel coincides with that of the casing. This symmetrical arrangement assures a balance of forces within the liquid ring and acting on both the wheel and the casing. As a result, currents or vortexes created as the liquid ring flows around the wheel are equal and cancel one another as they pass the wheel.

A gravity fed arrangement is provided for maintaining the liquid level in the ring at its desired level. This gravity fed device will both automatically supply liquid when it is required and siphon off liquid when excess liquid is present. This device, like the porting arrangement, has no moving parts. In addition, the liquid level control is, in its preferred embodiment, adjustable so that one may select an appropriate and adjusted liquid level.

The combination of features referred to above not only prov-ides increased efficiencies, but in so doing also provides high pressures and high volume outputs well beyond those which are obtainable with known liquid ring devices. This is because high velocities now obtainable through the features of this invention greatly increase the pressure output, which varies with the difference between the square of the velocity of the liquid and the square of the velocity of the cavity in which the gas is being compressed.

Accordingly, the objects of this invention are to provide a novel and improved gas compressor of the liquid ring type and a method operating such a compressor.

Although the invention is described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form is made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

In the accompanying drawings:

FIGURE 1 is a vertical, transverse sectional view of the compressor of the present invention, taken along the line 11 of FIGURE 2, and looking in the direction of the arrows;

FIGURE 2 is a horizontal plan view of the compressor of FIGURE 1, taken along the line 22 of FIGURE 1 and looking in the direction of the arrows;

FIGURE 3 is a plan view in part broken away and with parts in section of the compressor of FIGURE 1 taken along the line 3-3 of FIGURE 1 and looking in the direction of the arrows; and

FIGURE 4 is a fragmentary transverse sectional view of the compressor showing another embodiment of a wave suppressor.

Referring now to the drawings, the main body of the compressor is in the form of a circular cylindrical casing 10. The casing is shown disposed for rotation about a vertical axis. It should be recognized that the device will operate with rotation about a horizontal axis or any other. The casing 10 is comprised of a peripheral wall 12 which, in the orientation shown, is upstanding. The wall 12 extends between spaced lower and upper radial Walls 14, 15. A central opening 18 of circular shape is provided in the upper radial wall 15. The opening 18 is generally centered with the vertical, central axis of the circular casing 10. A central boss 20 is located on the lower radial wall 14 of the circular casing 10, along the central axis.

A downwardly extending vertical shaft 21 is fixed to the circular casing 10 at the boss 20, as by screw threads or other suitable means. The shaft 21 supports the circular casing 10 in a fixed support 23 for rotation in bearings 24. A prime mover, such as an electric motor 26, is connected to the vertical shaft 21 of the circular casing 10. Energization of the motor 26 rot-ates shaft 21 and circular casing about the central axis of the casing and shaft.

A plurality of generally radially extending vanes 30 are mounted adjacent the inner surfaces of the lower and upper radial walls 14, 15. As best shown in FIGURE 2, the vanes are coterminus at one end with the peripheral wall 12 of the circular casing 10. The radial extent of the vanes from the wall 12 terminates somewhat short of mid-way to the center axis of the circular casing 10. The vanes 30 are curved along their radial extent, most sharply adjacent the inner surface of the wall 12. Curved arrows in FIGURES 2 and 3 show the direction of rotation of the circular casing 10. The vanes 30 curve so the outermost end of each vane, adjacent the wall 12, is curved toward the direction in which the casing 10 rotates. Inner radially extending edges 32 of each vane 30 include a recessed or notched portion 34 spaced from either end of each vane 30. An annular wall 35 is located within the notches 34 flush with the edges 32 of the vanes that are carried on the radial wall 14. A similar annular wall 36 is provided in conjunction with the vanes 30 carried on the radial wall 15. Thus, as best shown in FIGURE 1, the annular walls 35 and 36 are spaced from the radial walls 14 and and are located intermediate the ends of the vanes 30. The innermost circular edge of each annular wall 35, 36 is positioned at a radial location that is slightly below but adjacent the surface of the liquid ring that is carried within the casing 10 during operation. By so locating the annular walls with respect to the liquid ring level, the amplitude of harmonic waves that tend to be formed in the rotating liquid ring is limited. As will be more clear subsequently, the liquid surface is also located adjacent the radial location of the root of each cavity of the wheel of the device at the point of maximum wheel immersion in the liquid ring.

A second fixed support 40 extends from above the circular casing 10 downward through the circular central opening 18 in the upper radial wall 15 of the casing. The fixed support 40 is generally circular in plan, and smaller than the central opening 18. See FIGURES 1 and 3. A through-bore 41 extends vertically through the fixed support 40 and houses a rotatable shaft 43. The shaft 43 is journaled in a bearing 44 that is retained by a ring 45. The shaft 43 extends in a vertical direction parallel with the shaft 21 of the circular casing 10, but olfset horizontally with respect thereto, in the orientation of FIGURE 1.

A compression wheel 48 having a cenral raised hub 49, is fastened directly to the lower end of the shaft 43 adjacent the bottom of the fixed support 40, and is located within the circular casing 10. The relationship among the fixed support 40, the compression wheel 48, and the circular casing 10 is such that the central radial plane of the compression wheel 48 coincides with a central radial plane through the circular casing 10. That is, the compression wheel 48 is located mid-way between the upper and lower radial walls 14 and 15 of the circular casing 10. Because of the offset relationship between the shafts 43 and 21, the axis of the rotation of the compression wheel 48 is eccentrically located with respect to the axis of rotation of the circular casing 10. The central opening 18 in the upper radial wall 15 of the circular casing 10 facilitates rotation of casing 10 with respect to the eccentric mounting of the fixed support 40. A means for rotating and/ or controlling the speed of rotation of the wheel 48, such as an electric motor or generator (i.e., brake) is fastened to the upper end of the shaft 43. Other means for controlling the rotation of the wheel 48 are also contemplated. For example, the wheel 48 may be directly driven in a predetermined relationship to the rotation of the casing 10 by a gear drive from the driving shaft 21 to the shaft 43, thereby obviating the need for the motor 46.

The compression wheel 48 is circular in plan, uniform in thickness, i.e., in transverse cross section, throughout a solid central portion, and is tapered adjacent the peripheral portion to a reduced thickness at the perimeter. The peripheral portion of the wheel 48 is formed of spaced upper and lower generally radially extending annular walls 53, 54. Radially inward portions of the walls 53, '54 are essentially coextensive with upper and lower radial surfaces 55, 56, respectively, of the central portion of the wheel 48. The walls 53, 54 are equal in length. Radially outwardly of the coextensive portions, the walls 53, 54 curve inwardly symmetrically toward one another and the radial center plane of the compression wheel 48. Thus, the walls 53, 54, provide the sides of an annular recess or channel about the perimeter of the wheel 48. The base of this channel is defined by a concentric cylindrical back surface or channel root '57. Because of the curvature of the walls 53 and 54, the channel formed is narrower at the opening about the perimeter of the wheel 48 than it is at the back or inner surface 57.

A plurality of curved vanes 59 extend from the inner surface 57 of the annular channel, between the walls 53 and 54, to the perimeter of the wheel. The vanes 59 define a plurality of individual cavities 60 about the perimeter of the compression wheel 48. By virtue of this construction, each cavity 60 has an inlet opening of smaller cross section than the cross section of the cavity inwardly of the opening. The vanes 59 extend generally radially of the wheel 48 at the wall 57, but curve along their length to extend generally away from the direction of wheel rotation adjacent the perimeter of the wheel. As best shown in FIGURES 2 and 3, the eccentric mounting of the compression wheel 48 within the circular casing 10 positions the cavities 60 closer to the peripheral wall 12 of the circular casing 10 at a fixed location with respect to the fixed support 40. As mentioned previously, the back wall or root 57 of each cavity 60*, at the location where the cavities are closest to the wall 12, is positioned at a radial distance from the wall 12 that corresponds generally to the nominal depth of the liquid ring.

A porting passageway 62 extends diagonally through the compression wheel 48 from the back surface 57 of each cavity 60 to the upper radial face '55 of the compression wheel 48. The porting passageways 62 form a ring of spaced apertures 62 in the upper radial face of the compression wheel 48 located inwardly of the cavities 60.

A fixed valve shoe 66 is formed in the fixed support 40.

The valve shoe 66 has a fiat bottom surface 68 positioned in sliding and sealing relationship with the underlying portion of radial face of wheel 48. The valve shoe extends upwardly at an angle from the flat bottom surface 68 and curves in a generally arcuate configuration of sufiicient length to overlie a plurality of the porting passageway apertures 63. An elongated arcuate passageway 70 opens through the bottom surface 68 extends through the valve shoe 66 at an angle corresponding with the angle of the porting passageways 62. The passageway 70 curves within the valve shoe 66 and extends part way along the length so as to directly overlie some but not all of the porting passageway apertures 63 that are beneath the shoe surface 68. The passageway 70 is connected to a discharge passageway 72 through which gas compressed in the cavities is discharged.

As indicated by the curved arrow in FIGURE 3 showing the direction of rotation of the compression wheel 48, the passageway is located adjacent the far end of the flat bottom surface 68 of the fixed valve shoe 66, relative to the movement of the cavities 60 with respect to the valve shoe. The first portion of the valve shoe 66 is solid, as shown in FIGURE 3, and serves to seal the porting passageways 62 as the apertures 63 pass beneath the first portion of the valve shoe 66. The valve shoe 66 is located just in advance, considering the direction of rotation of the compression wheel 48, of the point where the periphery of the compression wheel comes closest to the inner peripheral wall 12 of the circular casing 10. That is, the valve shoe is positioned to seal the aperture 63 to the porting passageway 62 of each cavity 60 as the cavity enters a ring of liquid 73 maintained within the circular casing 10, and the passageway 70 is positioned to open the aperture 63 after the cavity 60' has rotated to the point where it is partially submerged in the liquid ring. The length of the passageway 70 maintains the passageways 6-2 open until the cavity 60 is completely submerged and the liquid level of the ring has essentially reached the inner or back wall 57. The shoe 66 then terminates where the cavities 60 begin to move away from the peripheral wall 12 of the circular casing 10 during rotation of the wheel 48, at which point the porting passageways 62 communicate directly with the ambient atmosphere, permitting the cavities 60 to be removed from the liquid ring without creating a vacuum in the cavities.

A level control tube 75 extends through the central opening 18 in the circular casing 11 to one side of the compression wheel 48. The lower end of the control tube 75 is curved as at 76 so that an open end 77 faces into the direction of rotation of the circular casing 10'. The opening 77 is positioned in the central radial plane of the circular casing 10 and the compression wheel 48, and may be positioned at various locations within this plane radially of the casing 10. Directly above the level control tube 75, as oriented in FIGURE 1, is a reservoir 78 for containing liquid of the liquid ring within the circular casing 10. A pressure balance is established between the moving liquid in the casing 10 and the liquid in the reservoir '78 that maintains the liquid level in the casing at the depth to which the open end 77 is located within the casing 10. Movement of the open end 77 of the control tube 75 radially away from the peripheral wall 12 of the casing 10 will introduce more liquid to the ring from reservoir 78, and movement toward the wall 12 will remove liquid from the ring to reservoir 78.

As shown in FIGURES 2 and 3, a stationary baffle 80 that is fixed to the support 40 is positioned to closely encircle a portion of the compression wheel 48 about the perimeter. The baffie is wide enough to span the opening between the cavity walls 53 and 54 and is long enough so that it encircles a sufiicient portion of the perimeter of the wheel 48 to completely seal the opening of a cavity 60. Preferably, it is somewhat longer than the length of the opening of each cavity 60. The baffie extends partially without the liquid ring and partially within the ring and is adapted to seal the opening of each cavity 60* from the ambient atmosphere as the cavity enters the ring of li uid.

For purposes of illustration, the above-described apparatus is shown in FIGURE 1 housed within a hermetically sealed container 90 having an inlet 91. The discharge passageway 72 and the leads to motors 26 and 46 extend through sealed openings in the container wall. Thus, gas can be introduced through inlet 91 where it will be re ceived the casing 10 and be compressed and discharged through the passageway 72.

In operation, liquid, such as water, is placed within the circular casing 10. The casing 10 is rotated about its central axis on shaft 21. This rotation causes the liquid within the casing 10 to rotate and centrifugal force forms a ring of liquid 73 about the peripheral wall 12, extending partially up the radial walls 14 and 15. A quantity of liquid is used that will establish a ring of liquid of a depth just beyond the inner edge of each annular wall 35, 36. The depth of the liquid at the radial center plane of the circular casing is only suflicient to completely submerge the cavity 60 of compression wheel 48 that is closest to the peripheral wall 12, and may, in some instances, be slightly shallower. This relationship is shown schematically in FIGURES 2 and 3.

The radially extending, curved, vanes 30 on the two side walls 14 and 15 of the casing 10 effectively couple the liquid ring with the rotating casing. The vanes put energy into the liquid as the casing 10 is rotated by motor 26. Because the fluid coupling provided by the vanes 30 puts energy into the liquid rather than takes it out, there is a reduction in hydraulic losses. This arrangement provides an efficient Way of replenishing the energy lost by the liquid flowing past the compression wheel 48. Moreover, a coupling configuration that maintains a velocity profile in the liquid most nearly approximating rigid body rotation results in the lowest hydraulic losses. In the present invention, such a profile is maintained by virtue of fluid effiux from the coupling vanes in the direction of rotation at the outside diameter of the coupling, i.e., adjacent a peripheral wall 12. Furthermore, by maintaining the liquid velocity in the casing at the casing speed, there is a high compression potential relative to the slower moving cavities of the compression wheel 48.

The construction of the vanes 30 and the annular walls 35 and 36 recessed in the notches 34 of the vanes establishes circulating currents within the liquid ring. These currents flow from the intermost end of the vanes 30 toward the peripheral wall 12, between adjacent vanes and behind the adjacent annular walls 35 and 36, and thence out from between the vanes adjacent the peripheral wall 12 toward the central radial plane of the casing 10. The currents then flow back toward the surface of the liquid ring in front of, i.e., between, the walls 35, 36. This flow serves to effectively couple the liquid ring to the casing 10.

With the upper edges of the annular walls 35, 36 located just below the surface level of the liquid ring, any wave that is formed tends to wash over the wall and its energy is dissipated. In this way, the walls limit the amplitude of any wave disturbance on the surface of the liquid ring and permit high rotational speeds. To facilitate this functioning of the annular walls with small variations in liquid level in the casing, radial slots or notches (not shown) may be placed in the walls at the inner edges. Lateral flow of liquid through the slots and between the vanes will dissipate energy of any waves formed, even before the wave flows over the inner edges of the walls. As an alternative to utilizing the walls 35, 36, as wave suppressors, a short annular projection or ring 38 (FIGURE 4) may extend at right angles adjacent the inner surface of each wall 14, 15, and adjacent the surface of the liquid ring. Any increase in liquid level due to the formation of waves will cause the liquid to flow onto the extending surface of the ring and the energy of the wave will be dissipated. Such a ring is particularly effective where it has spaced grooves 39 or, alternatively, slots or apertures in its surface for discharging any liquid that flows onto the extending surface.

The depth of the liquid ring within the circular casing 10 at the radial center plane of the casing is determined by the location of the open end 77 of the level control tube 75. It will be understood that the surface of the liquid ring is essentially vertical in the ring as oriented in FIGURE 1 and that the end 77 of the control tube is adjacent the surface of the liquid ring. Movement of the level control tube toward the peripheral wall 12 of the circular casing 10 causes the open end 77 of the tube to enter the liquid ring beyond an equilibrium position. Because the ring is in rotation, liquid will be forced into the opening 77 and up the tube 75 to the reservoir 78. As a result, the level of the liquid in the casing 10 will diminish. As it does, the pressure on open end 77 diminishes until the pressure of the liquid in the ring balances the hydrostatic pressure of the liquid in the reservoir 78. If the open end 77 of the level control tube 75 is moved farther away from the peripheral wall 12, liquid will flow from reservoir 78 into the casing 10 to increase the depth of the liquid ring. The depth increases until the level of the liquid ring produces a pressure against opening 77 that balances the hydrostatic pressure of the reservoir 7 8. With this arrangement, it is possible to conveniently and accurately regulate the level of the liquid ring within the casing 10.

The speed of rotation of the circular casing may be accurately controlled by motor 26. As the casing 10 and liquid ring rotate, the liquid exerts a rotational force upon the compression wheel 48. In addition, a rotary control means, such as the motor or brake 46 attached to the end of shaft 43, will maintain the compression wheel 48 at a given rotary and hence peripheral speed by either rotating the wheel 48 or by resisting rotation of the wheel 48 caused by the moving liquid ring. In this manner, the compression wheel 48 is rotated in the same direction as the circular casing 10 and liquid ring, but at a lower peripheral speed. Alternatively, the wheel may be gear driven in rotation from the casing or casing drive so as to be directly synchronized with the casing rotation. In such a case, the selection of gears will determine the relative speeds of rotation of the casing and wheel.

As best shown in FIGURES 2 and 3, as the compression wheel 48 rotates, successive cavities 60 are submerged in the liquid ring adjacent the location of the bafile 80 and emerge from the liquid ring after rotating through about 160 degrees. Approximately mid-way between these two points, where the perimeter of the compression wheel 48 comes closest to the peripheral wall 12 of the casing 10, the cavities 60 become completely submerged within the liquid ring. From the point of entrance into the liquid ring to the point of complete submergence, the volume within each cavity 60 is gradually and progressively diminished. Thus, gas trapped within the cavity by the liquid of the ring is compressed. During the initial stages of compression, the outlet aperture 63 of the porting passageway 62 of each cavity 60 is sealed by the solid flat bottom surface 68 of the fixed valve shoe 66. Upon further rotation of the compression wheel 48, the aperture 63 previously sealed is ported to the elongated passageway '70 and the discharge passageway 72. Thus, the liquid of the ring forces the trapped gas within each cavity 60, under pressure, through the passageway 70 to the discharge passageway 72 of the compressor. At the location where each cavity 60 becomes completely submerged and where all the trapped gas has been forced under pressure through the passageway 70, the porting passageway 62 passes from beneath the valve shoe 66 and vents the cavity 60 to the surrounding atmosphere within the circular casing 10. Further rotation of the cavity tends to remove the cavity from the liquid ring. Because the cavities are ported to the ambient atmosphere via passageways 62, there is little or no suction created within the cavities during removal. The liquid within the cavities is therefore not carried from the ring in the cavities as it otherwise would be without venting. This materially reduces cavitation. Because the porting passageways are vented at the point where the liquid of the ring reaches the inner wall 57, any further flow of liquid into the cavity due to the higher velocity of the liquid ring is not carried into the discharge passageway, but merely escapes to the top surface of the wheel 48 beyond the valve shoe 66.

As has already been explained above, the vanes 59 of the compression wheel 48 curve away from the direction of rotation. This, coupled with the greater peripheral speed of the liquid ring in the casing 10, provides a relationship in which the kinetic energy of the rotating liquid ring is used along with the hydrostatic pressure of the liquid in compressing the gas within each cavity 60. That is, a velocity head or kinetic energy head is produced that acts upon the trapped gas and tends to compress the gas. Utilization of the kinetic energy of the liquid ring is enhanced through the improved configuration of the cavity 60. Each cavity 60 widens in cross section from the opening at the perimeter of the compression wheel 48 toward the back or inner surface 57. The cavity therefore functions as an expander or mechanical diffuser with respect to the moving liquid of the rotating ring, and changes the kinetic energy of the moving liquid into a static pressure head as the liquid flows into the cavity. In this manner, a high pressure is produced within each cavity 60 that is not solely dependent upon the hydrostatic pressure head produced as a function of the depth to which the cavity 60 is submerged into the liquid ring. For this reason, the cavities need not be deeply submerged to obtain high pressures, and in some instances need not even be submerged to the depth of the back wall or cavity root 57. This is, of course, advantageous because it reduces body drag of the wheel in the liquid ring.

The baffle cooperates with each cavity 60 as the cavity enters the liquid ring of the casing 10 to seal the cavity from the ambient atmosphere just prior to and during submergence into the liquid. This prevents the gas within each cavity from being partially displaced by the liquid as it otherwise would be until the trailing vane of the cavity enters the liquid. It does this by providing an effective seal over each cavity as the cavity enters the liquid ring, thereby holding in the trapped air until the trailing vane enters the liquid ring. This improves the volumetric efiiciency of the compressor. In addition, the bafile, by delaying somewhat the entrance of liquid into the cavity, helps to seal the cavity with a uniform liquid velocity front, improving the utilization of the kinetic energy of the moving liquid ring.

Because the circular casing 10 and the liquid ring contained therein are rotating at a faster peripheral speed than the compression wheel 48, the wheel 48 creates a drag against the movement of the liquid ring. This drag results in a loss of energy in the system. By virtue of the tapered cross sectional shape or streamlining of the compression wheel 48, the drag resistance of the compression wheel is materially reduced.

In constructing the compressor of the present invention, a substantial clearance is provided between the annular side walls 53 and 54 of the compression wheel 48 and the adjacent radial walls 15 and 14, respectively, of the circular casing 10. That is, the peripheral portion of the compression wheel 48 that is immersed within the liquid ring is kept sufficiently small so as not to cause undue acceleration of the flow of liquid of the ring through the restricted passageway created as a result of the submergence of the compression wheel within the path of liquid flow. It will be understood that in a rotating liquid ring where the liquid flows past the compression wheel, there is an increased velocity and elevation of the liquid surface. This results in a reduction in the efiiciency of the compressor due to increased body drag and turbulence caused by the change in the cross sectional area of the liquid. The severity of the turbulence and energy loss is a function of the proportion of the liquid ring that is blocked. In order to limit such losses to an acceptable level, no more than 80 percent of the original cross section of the liquid ring, including the coupling vanes, should be obstructed by the wheel at the point of maximum submergence of the wheel in the liquid ring. This is particularly important at high rates of linear velocity of the liquid ring, which are obtainable with the liquid coupling vanes of the casing and which can be utilized to good advantage in the design of the present invention. Thus, with no more than 80 percent of the liquid ring area, as already defined, obstructed, efiicient operation can be obtained at substantial linear velocities of the liquid ring, for example, at velocities of 50 feet per second and above. On the other hand, there is little additional benefit to be gained once the obstructed cross section of the liquid ring is maintained as small as one half of the liquid ring area.

By way of example only, a compressor has been constructed embodying the inventive concepts of the present invention and in which a compression wheel 3 inches in diameter was positioned within a casing 5 inches in diameter in the manner shown in FIGURE 1. The walls 14, 15 of the casing were 2 inches apart and approximately 25 ounces of water were contained in the casing. The wheel was inch thick at the root of the cavities and A inch thick at the cavity openings. Twenty-four cavities 6 inch deep were spaced about the periphery. A level 1 1 control tube was positioned to locate the surface of the liquid ring just above the inner edges of the annular walls 35, 36 and approximately even with the back wall 57 of the most completely immersed cavity.

The outer casing 10 was rotated at a speed of 8000 revolutions per minute and the compression wheel 48 was rotated in the same direction at a speed of 6500 revolutions per minute. This established a depth of the liquid ring 73 of about /2 inch at the center plane of the casing 10. With the compressor operated under ambient conditions where the air pressure is approximately 14.7 pounds per square inch gauge and the air temperature is approximately 68 degrees Fahrenheit, a compressed gas pres sure in excess of 65 pounds per square inch absolute has been produced. Of this pressure, it is calculated that at least 80 percent is produced by the kinetic energy of the liquid ring. Such a compressor can attain a single stage pressure ratio greater than 5 to l, at an air flow rate of 2.5 cubic feet per minute, and with a hydraulic efiiciency greater than 80 percent.

While the above described example sets forth a specific mode of operating the disclosed compressor, it will be understood that the circular casing and the compres sion wheel 43 may be rotated at different speeds from those specified. It is contemplated, however, that the direction of rotation of both the compression wheel 48 and the circular casing 10 will be in the same direction, and that the peripheral speed of rotation of the circular casing 10 and liquid ring will be greater than the peripheral speed of the compression wheel 48. It is the difference in speed and the improved shape of the cavities 60, that provide and utilize the kinetic energy of the velocity head of the liquid ring. While even small differentials in peripheral speed will produce a finite kinetic energy component, full advantage of the present teachings are utilized by establishing a differential peripheral speed sufiicient to produce a kinetic energy component contribution that is at least equal to 10 percent of the total pressure produced upon the gas in the cavities of the compressor wheel. Outstanding results have been obtained when the differential peripheral speed between the liquid ring and the compression wheel is about 75 feet per second, in which case the kinetic energy pressure component may well exceed 80 percent of the total pressure produced. In most instances, for efficient utilization of the compressor, the wheel will be rotated at a linear speed no greater than 0.9 times the linear speed of the liquid ring and easing, allowing a recovery of at least about one-fifth of the kinetic energy available. With a larger speed differential, for example, where the wheel speed is only one-half that of the liquid, approximately three fourths of the available kinetic energy of the liquid ring is recovered. It will be recognized, of course, that a balance must be reached because increases in pressure produced by large dilferentials in wheel and liquid ring speed necessarily decrease the volume of gas compressed by the compressor.

By way of comparison, in the known Nash type compressor, which appears to be the only liquid ring type compressor that has been put to significant use, a pressure rise of to pounds per square inch may be obtained and the compressor is operated at peripheral speeds of up to about feet per second. Beyond such speed, vibrations, waves, and blocking of the water by the wheel prevent operation. With the compressor of the present invention, peripheral speeds of to feet per second are not unusual without encountering destructive wave disturbances or excessive vibration. Accompanying pressure rises of 100 to pounds per square inch are obtained. At the same time, the volume of gas supplied by the compressor is greatly increased over known liquid ring compressors.

What is claimed is:

1. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber;

(b) a compression wheel eccentrically mounted within the chamben'the wheel including a plurality of compression cavities and means for porting compressed gas from the cavities;

(c) drive means coupled to the wheel and to the casing to positively rotate both the Wheel and the casing; and,

(d) the casing including fluid coupling means within the chamber and adapted to drive a ring of liquid therein, said coupling means comprising first and second sets of generally radially disposed vanes extending inwardly from casing walls that define sides of the chamber and curving along their length so the outermost end of each vane is curved toward the direction in which the casing is rotated.

2. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber adapted to contain a liquid;

(b) means mounting the casing for rotation about a central axis perpendicular to the circular form of the chamber;

(c) means for rotating the casing about the central axis at a sufiicient speed to form a ring of liquid within the casing;

(d) a wheel located within the casing and having a central axis of rotation parallel to but displaced laterally from the central axis of the casing, said wheel being eccentrically located so that the perimeter is adapted to be in part submerged in a ring of liquid within the casing;

(e) a plurality of cavities in the wheel opening through the perimeter of the wheel;

(f) porting means operatively associated with each cavity to permit the escape of gas compressed in each cavity;

(g) means operatively associated with the wheel and the porting means to selectively prevent and permit the escape of gas compressed in each cavity;

(h) means mounting the wheel for rotation about the central axis of rotation;

(i) means for controlling the rotation of the wheel;

and

(j) a bathe in a fixed position within the casing closely adjacent the periphery of the wheel and partially immersed within the liquid ring, said bafile being so constructed and arranged to seal any unimmersed portion of the opening of a cavity as the cavity enters the liquid ring from the surrounding atmosphere, thereby preventing gas displaced in the cavity by liquid from escaping from the cavity even though the cavity opening is not yet completely immersed.

3. In a liquid ring mechanism, the combination of:

(a) a rotatable casing defining a circular chamber;

(b) fluid coupling means within the casing and operably associated therewith to drive a ring of fluid therein;

(c) means within the casing for limiting the amplitude of wave disturbances in a liquid ring within the casing;

(d) a rotatable compression wheel within the chamber, the wheel including a plurality of compression cavities and means for porting compressed gas from the cavities;

(e) drive means to rotate the casing, and

(f) means controlling the speed and direction of rotation of the wheel.

4. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber;

(b) means mounting the casing for rotation about a central axis of the casing;

(c) a compression wheel located within the chamber;

((1) means mounting the wheel for rotation about a central axis of the wheel;

(e) fluid coupling means within the chamber for driving a ring of fluid within the chamber;

(f) means for rotating the casing at a peripheral speed;

(g) means controlling the rotation .of the Wheel to establish a peripheral speed of the wheel in the direction of casing rotation that is at least 10 percent slower than the peripheral speed of the casing; and

(h) means including a plurality of compression cavities in the wheel, each having an inlet formed to receive a velocity component of a ring of fluid rotated with the casing at a faster speed than the wheel and an outlet that is effectively closed during a portion of the wheel rotation, to eifectively recover and utilize kinetic energy of such ring.

5. in a method of compressing gas with a liquid, the

steps comprising:

(a) forming a rotating ring of liquid;

(b) rotating the ring of liquid at a first peripheral speed;

(c) rotating a wheel in a plane of and encircled by the ring, in the same direct-ion as the ring, and at a slower peripheral speed, said wheel having cavities with openings in the periphery of the wheel;

(d) allowing cavities to fill with gas during rotation of the wheel;

(e) receiving in the wheel cavities a flow of liquid from the ring entering the cavity openings at a velocity caused by the greater peripheral speed of the ring and thereby creating increased pressure within the cavities from the kinetic energy of the ring; and

(f) emptying the cavities of liquid during each revolution of the wheel.

6. *In a method of compressing gas with a liquid ring mechanism having an outer rotatable casing containing a liquid and a rotatable compression wheel within the casing, the wheel including a plurality of open-ended compression cavities about its periphery, the steps comprising rotating the casing at a first peripheral speed sufficient to form a ring of liquid within the casing, rotating the wheel at a peripheral speed slower than the said first peripheral speed, intercepting liquid of the ring moving with the casing, progressively decelerating the intercepted liquid by increasing the cross sectional area progressively available to the liquid whereby kinetic energy of the moving liquid is converted to static pressure energy, and compressing gas in the cavities of the wheel with theliquid.

7. The mechanism of claim 1 including two annular walls, one well being aflixed to the innermost radially extending edges of the first set of vanes and the other being similarly afiixed to the second set of vanes, said walls terminating short of the radial ends of the v-anes, thereby forming a plurality of peripherally speed openended radially extending conduits on the inner sides of the casing walls.

8. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber;

(b) a compression wheel eccentrically mounted Within the chamber, the wheel including a plurality of compression cavities and means for porting compressed gas from the cavities;

(c) drive means coupled to the wheel and to the casing to drive both the wheel and the casing; and,

(d) each of said cavities being disposed adjacent the perimeter of the wheel and having an inlet opening of smaller cross section than the cross section of the cavity inwardly of the opening whereby each cavity is a mechanical diifuser.

9. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber;

(b) means to support the casing for rotation about a central axis of the circular 'form;

() a compression wheel eccentrically located within the chamber, the wheel including a plurality of compression cavities and means porting the cavities to remove compressed gas, said cavities (i) being located about the periphery of the wheel (ii) having inlet openings at the outermost perimeter of the wheel, and

(iii) having inlet openings of smaller cross section than the cross section of the cavity inwardly of the opening;

(d) means separate from the casing to support the wheel for rotation about the center of the wheel; and

(e) means to 'drive the casing in rotation about the central axis.

10. The mechanism of claim 9 including means to control rotation of the wheel about its center.

11. In a method of compressing gas with a liquid ring mechanism having an outer rotatable circular casing containing a liquid, and a rotatable compression wheel located eccentrically within the casing, the wheel including a plurality of open-ended compression cavities about its periphery, said wheel cavities having outer extremities displaced angularly about the wheel with respect to inner ends of the cavities in a direction opposite to the direction of wheel rotation and being adapted to be serially submerged in the liquid of the casing and thereby entrap gas to be compressed, and then be emerged from the liquid, said cavities being ported to allow the removal of gas compressed after the cavities have been submerged, the steps comprising rotating the casing containing the liquid at a first peripheral speed sulficient to form a ring of liquid within the casing, rotating the wheel in the same direction as the casing at a second peripheral speed slower than the said first speed, controlling the speed of the wheel relative to the speed of the casing and liquid, and recovering with the wheel kinetic energy from the liquid moving at a greater peripheral velocity than that of the wheel.

12. In a method of compressing gas with a liquid ring mechanism having an outer rotatable circular casing containing -a liquid, and a rotatable compression wheel located eccentrically within the casing, the wheel including a plurality of open-ended compression cavities about its periphery, said wheel cavities having outer extremities displaced angularly about the wheel with respect to inner ends of the cavities in a direction opposite to the direction of wheel rotation and being adapted to be serially submerged in the liquid of the casing and thereby entrap gas to be compressed, and then be emerged from the liquid, said cavities being ported to allow the removal of gas compressed after the cavities have been submerged, the steps comprising rotating the liquid to form a liquid ring rotating at a first peripheral speed and in which the eccentrically located wheel becomes partially immersed, the ring thereby exerting a rotational force on the wheel; limiting the peripheral speed at which the wheel is rotated to a predetermined second velocity less than the first velocity of the moving ring of liquid, and recovering with the Wheel kinetic energy from the liquid moving at a greater peripheral velocity than that of the wheel.

13. The method of claim 12 wherein the greatest kinetic pressure component created at the opening of the cavities is at least 10 percent of the total pressure produced upon the gas in the cavities of the compression wheel.

14. The method of claim 12 wherein both the wheel and the liquid ring are rotated in the same direction.

15. The method of claim 14 wherein the second velocity is no greater than percent of the first velocity. 16. In a liquid ring mechanism, the combination of:

(a) a casing defining a circulator chamber adapted to contain a liquid;

(b) means mounting the casing for rotation;

(c) a compression wheel eccentrically located within the chamber, the wheel including a plurality of compression cavities having openings through the perimeter of the wheel and means for porting compressed gas from the cavities;

((1) means mounting the Wheel for rotation;

(e) means to rotate at least one of the casing and the wheel and thereby form a rotating liquid ring in which some of the cavities of the wheel are submerged; and

(f) a stationary solid bafile closely encircling a portion of the wheel perimeter, said baflie being at least as wide and long as the width and length of each of the openings of the cavities in the perimeter of the wheel, and located so that one edge of the bafile will extend into the liquid ring within the casing adjacent the point of entry of the cavities into the ring and another portion will extend out of the liquid ring so as to effectively cover each cavity opening as the cavity enters the liquid ring, whereby gas displaced in the cavity by liquid is prevented from escaping even though the cavity opening is not yet completely immersed in the liquid ring.

17. In a liquid ring mechanism, the combination of:

(a) a circular casing constructed and arranged to rotate about a central axis in one direction of rotation;

(b) a compression wheel eccentrically positioned within the casing and constructed and arranged to rotate about a central axis of the wheel in the same direction of rotation as the casing but at a significantly slower peripheral speed; and

(c) cavities within said wheel opening through the perimeter of the wheel, said cavities being defined in part by generally radially extending vanes within the wheel, which vanes curve adjacent the perimeter of the wheel where liquid enters the cavities so as to extend in a direction generally away from the direction of wheel rotation, whereby the outer end of each cavity is angularly displaced about the wheel periphery from the inner end in a direction opposite to the direction of wheel rotation and kinetic energy of a liquid ring rotated by the casing can be effectively utilized by the compression wheel.

18. In a liquid ring mechanism in which a rotary compression Wheel having peripheral cavities opening through the perimeter is eccentrically located within a rotary casing adapted to contain a liquid ring in which the periphery of the compression wheel is partially submerged, and including means to rotate the liquid ring and control the speed of the wheel, the improvement which comprises a generally tapered peripheral portion on the compression wheel such that a radial cross section of the peripheral portion of the wheel that becomes submerged in the liquid ring is narrowest adjacent the openings of the cavities and widens inwardly.

19. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber adapted to contain a liquid;

(b) means mounting the casing for rotation;

(c) a compression wheel eccentrically located within the chamber, the wheel including a plurality of compression cavities having openings through the periphcry of the wheel and means for porting compressed gas from the cavities;

(d) means mounting the wheel for rotation;

(e) means to rotate the casing and the wheel to form a rotating liquid ring that moves at a greater peripheral velocity than the wheel and in which some of the cavities of the wheel are submerged;

(f) said cavities being formed with outer extremities defining the openings through the periphery of the wheel angularly displaced about the wheel periphery with respect to inner ends of the cavities in a direction opposite to the direction of wheel rotation;

(g) coupling means associated with the casing to impart rotational movement of the casing to the liquid ring; and

(h) said casing and compression wheel being so constructed and arranged that the wheel obstructs no more than 80 percent of the maximum liquid ring 16 cross section normal to the liquid peripheral velocity prior to wheel contact at the location of maximum submergence of the wheel in the liquid ring.

20. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber;

(b) a compression wheel eccentrically located within the chamber, the wheel including a plurality of compression cavities and means for porting the cavities to remove compressed gas;

(c) each of said cavities being disposed adjacent the perimeter of the wheel and having an inlet opening of smaller cross section than the cross section of the cavity inwardly of the opening whereby each cavity is a mechanical diffuser;

(d) drive means coupled to the casing to rotate the circular casing about a central axis;

(e) means coupled to the compression wheel to control the speed of rotation of the wheel within the chamber;

(f) said drive means and said control means providing a significantly greater peripheral speed of the casing than of the wheel, both in the same direction of rotation; and

(g) fluid coupling means within the chamber for driving a ring of fluid within the chamber.

21. The mechanism of claim 20 wherein the cavities of the compression wheel are formed in part by radially extending vanes within the wheel, which vanes curve adjacent the perimeter of the wheel so as to extend in a direction generally away from the direction of wheel rotation.

22. The mechanism of claim 21 wherein the fluid coupling means include vanes extending from casing walls that define sides of the chamber.

23. The mechanism of claim 22 wherein the means for porting the cavities include a tube extending from each cavity and opening through a radial face of the wheel, and including a fixed valve shoe in sliding sealing relationship with the radial face of the wheel overlying a portion of the wheel face through which the porting tubes open, said valve shoe having a solid face portion abutting the radial face of the wheel for closing underlying openings through the radial face of the wheel and having an open portion in the face communicating with a discharge passageway to permit the escape of gas under pressure from the cavities through the porting tubes that underlie the open portion of the valve shoe.

24. The mechanism of claim 3 wherein the casing includes two spaced radial walls and the means of paragraph (c) includes an annular surface adjacent each radial wall at a location adjacent the level of the liquid ring within the casing.

25. The mechanism of claim 24 wherein the annular surface adjacent each radial wall is concentric with the casing and is constructed and arranged to dissipate the energy of wave disturbances on the surface of the liquid ring.

26. The liquid ring mechanism of claim 3 wherein the cavities of the wheel expand in volume in a direction from the periphery of the wheel centrally, and thereby form mechanical diffusers.

27. In a method of compressing gas with a liquid, the steps comprising:

(a) forming a rotating ring of liquid;

(b) immersing a wheel having a plurality of open cavities about its perimeter within the rotating ring of liquid to a depth Where the base of the most submerged cavity is substantially level with the surface of the liquid, the cavities of said wheel being formed with outer extremities defining the openings through the periphery of the wheel angularly displaced about the wheel periphery with respect to inner ends of the cavities;

(c) rotating the immersed wheel in a direction opposite to the direction in which the outer extremities of 1 7 the cavities are displaced with respect to inner ends thereof; and

(d) rotating the ring of liquid at a greater peripheral speed than the wheel is rotated and in the same direction, whereby kinetic energy is effectively recovered from the ring of liquid.

28. In a method of compressing gas with a liquid ring mechanism having an outer rotatable circular casing containing a liquid, and a rotatable compression wheel located eccentrically within the casing, the wheel including a plurality of open-ended compression cavities about its periphery, said wheel cavities having outer extremities displaced angularly about the wheel with respect to inner ends of the cavities in a direction opposite to the direction of wheel rotation and being adapted to be serially submerged in the liquid of the casing and thereby entrap gas to be compressed, and then be emerged from the liquid, said cavities being ported to allow the removal of gas compressed after the cavities have been submerged, the steps comprising rotating the liquid to form a liquid ring rotating at a first peripheral speed and in which the eccentrically located wheel becomes partially immersed, the ring there-by exerting a rotational force of the wheel in the same direction; and rotating the wheel at a predetermined, controlled, peripheral speed that is not greater than 90% of the peripheral speed of the liquid ring, and recovering with the wheel kinetic energy from the liquid moving at a greater peripheral speed than that of the wheel.

29. A liquid ring mechanism comprising a circular casing adapted to contain a liquid; means mounting the casing for rotation in a predetermined direction; a compression wheel eccentrically located within the casing; means mounting the wheel for rotation in the same direction as the casing; said wheel having a plurality of cavities defined in part by radially extending vanes curved adjacent the periphery of the wheel to extend in a general direction away from the direction of wheel rotation, said curved portion being located where the vanes intercept the inner periphery of a liquid ring that is formed When the casing containing liquid is rotated; means to rotate the casing at a first peripheral speed; and means to control the speed of rotation of the wheel so that it rotates at a peripheral speed no greater than 90 percent of the peripheral speed of the casing.

30. In a liquid ring mechanism, the combination of:

(a) a casing defining a circular chamber;

(b) a compression wheel mounted within the chamber,

the wheel including a plurality of compression cavities and means for porting compressed gas from the cavities;

(c) drive means coupled to the wheel and to the casing to drive the casing at a first peripheral speed and the wheel at a relatively lower peripheral speed; and

(d) means, including a plurality of vanes, providing with respect to the wheel periphery inner compression cavity portions located at points about the wheel periphery, and outer cavity portions extending therefrom and adapted to intercept and receive liquid carried by the casing at a location displaced angularly about the wheel periphery from the inner portions in -a direction opposite to the direction of wheel rotation;

(e) whereby kinetic energy of a ring of liquid rotated with the casing is efiectively utilized to compress gas in the compression cavities.

31. In a method of compressing gas with a liquid, the

steps comprising:

(a) forming a rotating ring of liquid;

(b) rotating the ring of liquid at a first peripheral speed;

(c) rotating a compression wheel within the casing in the same direction as the liquid ring, said wheel having peripheral compression cavities extending outward from inner ends to inlet ends for liquid;

(d) controlling the speed of the rotating wheel to estab- 18 lish a peripheral velocity significantly less than the velocity of the liquid ring; and,

(e) introducing liquid from the rotating ring to the cavities of the rotating wheels at a location outward of the inner end of each cavity and displaced angularly about the wheel periphery from the inner end in a direction opposite to the direction of wheel rotation;

(f) whereby kinetic energy of the liquid moving at a greater peripheral velocity than the wheel is effectively utilized to compress gas in the wheel cavities.

32. In a liquid ring mechanism, the combination of (a) a casing defining a circular chamber;

(b) means mounting the casing for rotation about a central axis of the casing;

(c) a rotatable wheel located within the chamber;

(d) means mounting the wheel for rotation about a central axis of the wheel;

(e) compression means, including peripheral cavities formed in said rotatable wheel with inner ends, and including curved deflector surfaces located outwardly from the inner ends of the cavities and displaced angularly about the wheel periphery from the inner ends of associated cavities in a direction opposite to the direction of wheel rotation;

(f) fluid coupling means within the chamber for driving a ring of fluid within the chamber;

(g) means for rotating the casing at a peripheral speed; and

(h) means controlling the rotation of the wheel to establish a peripheral speed of the wheel in the di rection of casing rotation that is at least 10 percent slower than the peripheral speed of the casing;

(i) whereby kinetic energy of a liquid rin-g adapted to be rotated by the casing can be eifectively utilized to compress gas in the peripheral cavities of the wheel.

33. In a liquid ring mechanism, the combination of (a) a casing defining a circular chamber;

(b) means mounting the casing for rotation about a central axis of the casing;

(c) a compression wheel located within the chamber,

the wheel including a plurality of compression cavities and means for porting the cavities to remove compressed gas;

(d) means mounting the wheel for rotation about a central axis of the wheel;

(e) fluid coupling means within the chamber for driving a ring of fluid within the chamber;

(f) means for rotating the casing at a peripheral speed;

(g) means controlling the rotation of the wheel to establish a peripheral speed of the wheel that is at least 10 percent slower than the peripheral speed of the casing; and

(h) means within and rotatable with the chamber to limit the amplitude of wave disturbances in a ring of fluid within the chamber while the chamber is rotated.

References Cited UNITED STATES PATENTS FOREIGN PATENTS 10/ 1933* Great Britain. 6/ 1932 Great Britain.

WILLIAM L. FREEH, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No 3 ,395 ,85 r August 6 1968 Cecil G. Martin et a1.

It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 13, line 52, "speed" should read spaced Signed and sealed this 21st day of October 1969.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, Jr.

Attesting Officer Commissioner of Patents 

